Work clamp mechanism



Dec. 5, 1944. DAVls WORK CLAMP MECHANISM Filed March 24, 1941 'sSheets-Skieet 1 awn/r01? n TfOR NE Y5 DCC. 5, 1944. E, DAVls WORK CLAMPMECHANISM Filed March 24. 1941 3 Sheets-Sheet 2 Dec. 5, 1944. DAVls WORKCLAMP MECHANISM Filed March 24. 1941 3 Sheets-Sheet 5IIIIIIIIIIIIIIIII'IIIIIII m f] g INVENTOR. MM BY ATTORNEYS Patentefc lDec. 5, 1944 i I UNITED STATES PATEN O F WORK CLAMP MECHANISM ErnestDavis, Syracuse, N. Y., assignorto The Prosperity Company, Inc.,Syracuse, N. Y., a corporation of New York i i Application March 24,1941, Serial No 384,788 q 7 Claims. ((21. 38-12) p This inventionrelates to work holders or work The invention comprises an inert body ormemclamps for garment and laundry pressing maber set inkmotion by anoperating movement of chines, and has for its object a readily operablea work holder or clamping member and free to work. clamp including aninert or. momentum lagjbehindandrun aheadofthe clamping mem body ormember set in motion by the initial closber, and hence gain momentumwhen lagging ing movement ofthe work holder orelamp and behind to runahead of the clamping, member operable to impart a delayed clampingeffect to and impart under the momentum an additional finally close theclamping member down on the operating impulse thereto. l work on thelower pressing element-under the The work clamp. mechanism hereillustrated momentum of the inert member. 10 comprises, generally, amanually operable clamp- It further has for its object an arrangementing member movable from an inoperative posiof the inert body or member,whereby the inert tion into and out of position to cooperate with membermoves into a position bywhich it rethe work on the lower pressingelement of the turns in aretrograde directionby gravity when machine, amovable inert body or member, means released, and. releasable meansoperable to hold 5 between the clamping member and the inert the inertmember in its operated position, and member to givea starting impulse tothe inert views.

. also a releasable means operable bythe operamember and set the same inmotion, when the tion of the press, particularly the opening move- Iclamping member is movedby theoperator from ment of the press. opentoward closed position, this means being This work holder isparticularly designed for constructed to permit the inert member t gapresses in which the force is applied by the op-- momentum and moveahead of the clamping erator in contradistinctionto a power press,.andmember. and exert a delayed clamping effect on one of the objects of theinvention is a work .the clamping member due. to the momentum holdermechanism involving an inert body or of the inert member or the energystored theremember that is operable with a minimum effort in, when theclamping member approaches its on the part of the operator, although thework final clamping position. l

holderis equally adaptable to power presses. In Figure "6 is illustratedone form of press- The invention consists inthe novel features ingmachine includingcoacting upper and lower and in the combinations andconstructions herepressing elements I, 2, the lower p g eleinafter setforth and claimed ment being suitably mounted on a frame 3, and 1 Indescribing this invention, reference is had the upper pressing elementbeing movable to-,. to the accompanying drawings inwhich like charwardand from the lower pressing element {and acters designate correspondingparts in all the carried by a lever 4 pivoted betweenits endsat l l 5 toan upright 6 rising from the frame. Figure 1 is a fragmentaryelevationlof this The press here shown is pedal operated. 1

work holder or clamping mechanism and condesignates the foot pedalpivoted at ,8 to the tiguous parts of the pressing machine, showingframe. The .motionis transmitted from the foot the said mechanism instarting position. pedal to the rear arm of the head carrying leverFigure 2 is a view similar to Figure 1 showing 4 through suitable means,as toggle links 9, ID. the W p ng mechanism in finally clamped pivotedtogether at like ends at H and :at their p s tio I l I l I otherends at[2 andl3 to the rear arm the Figure 3 is an elevationlooking to thelefthead carrying lever 4 and to the frame respecin Figure 2, andalsoillustrating a manuallyop- .tively. The motion of thefoot lever! istranserable release means. I p ferred to the link ID of the togglethrough suit- Figure 4 is a fragmentary plan view of parts ablemechanism, asa cam slot l4, provided in an seen in Figure 2, contiguousportionsof the pressarm of the link [0, and a follower or roller 15 ingmachine being omitted. I carried by the lever and movable along theslot. Figure 5 is a view similar to Figure 1 illustrat- In Figure 6, thepress is shown asclosed. When ing the means for automaticall releasingthe the press opens, the toggle 1inks9, [0 break or work clampingmechanismwhen the press opens. fold upwardly. The closing movementofuthe Figure 6.is an elevation, partly in section, of press is againstsuitable returning means, as a one form of pressing machine embodyingthis counter spring IS. The lower pressing element invention and showingone means for releasing 2 is usually covered with a resilient or springthe work clamp mechanism by. anjoperating padding I1.

movement ofthe press. The work holderor clamping member usual y moves orswings from a position beyond one end of the lower pressing element 2over the same and clamps substantially rectilinearly downwardly onto thework on the lower pressing element 2 or the padding thereof.

' 2| designates the clamping member, this including an arm 22 pivoted at23 to a suitable support or bracket 24, attachable to the frame 3 of thepressing machine, a yoke 25 carried by said arm and a tape or bow 26connected at its ends to the arms of the yoke. the pivot 23 are arrangedbelow one end of the pressing element 2 in such position that theclamping member normally stands in the position shown in Figure 1 beyondone end of the lower pressing element 2, and moves into a position inwhich the yoke is located under the pressing element 2 and the bow ortape extends transversely over the surface of the pressing element 2 inthe position shown in Figure 2. or in dash lines (Figure, 1). The endsof the bow or tape 26 are connected to the ends of the yoke byuniversaljoints, as ball and socket joints 21. The yoke is also providedwith a suitable handle 28.

29 designates the inert body or member, here shown as in the form of aquadrant or segment of a fiy wheel. It is pivoted on a horizontal axisat 30 to the support or bracket 24 and is here shown as pivotedbelow thepivot 23 of the arm 22 and movable from a depending static position(Figure l) upwardly into the position shown in Figures 2 and 5 under astarting impulse given to it by the clamping member 2|.

The means between the clamping member and the inert member to set thelatter in motion and permit it first to lag behind, second to gainmomentum, and finally overtake the clamping memembodiment of theinvention, motion transmitting connections including a reducingleverage, when the motionis being transferred from the clamping memberto the inert body or member and an increasing leverage when the motionof the inert body or member is being transferred to the clamping memberto give the latter a final impulse. These connections comprise a lever3| pivoted to the support or bracket 24 and here shown as pivotedcoaxially with the arm 22 on the pivot 23, one arm of the lever 3|coacting with the clamping member or the arm 22 thereof through yieldingmeansor springs 32, 33 and the other arm being connected to the inertmember 29 eccentric tothe axis 30 of the inert member, as through a link34 pivoted at 35 to the other arm of the lever 3| and at 36 to a rockarm 31 mounted on the pivot or shaft 30 of the inert member 29. One arm,as the arm below the pivot 23 of the lever 3|, and the link 34 are in anacute angle folded position (Figure 1) when the clamping member 29 is inits open position and move to a more open or obtuse angle relation, asthe clamping member 26 closes and the inert member or weight 29 hasmoved into its operated position (Figure 2). The spring 32 is located ona stud 38 projecting from the arm 22 between the head 39 of the stud anda head 40 on the lever 3|, and the spring 33 is interposed between thehead 40 and the arm 22. A suitable stop 4| on the bracket 24 limits theopening movement of the clamping member 2|. A stop 41!] on the inertmember coac s, with The arm 22 and a stop 4 on the bracket 24 to limitthe overthrow of the inert member under its momentum.

in operation, the operator by means of the handle 28 swings-the clampingmember 2| from the position shown in Figure 1 toward that shown inFigure 2. This through the spring 32 imparts a starting impulse to theinert member 29 through reducing leverage including the lever 3|, link34, and rock arm 31, starting the same in motion from the position shownin Figure 1. The inert member first, because of the spring 32, lagsbehind, then gains momentum and runs ahead of the arm 2|, and in sodoing, through the rock arm 31, link 34, lever 3|, which now acts in thereverse direction, as an increasing leverage, compresses the spring 33and applies final pressure to the arm 22 and the bow 26 causing the bowto move substantially rectilinearly onto the work 'on the lower pressingelement 2. The action of the inert member under the energy storedtherein is a delayed action between the starting of the inert member inmotion and the time the momentum overtakes the clamping member 2 i, thisbeing when the bow 23 is opposed to or down on the work on the lowerpressing element 2.' The delayed clamping action causes the bow totightly clamp on the Work.

The lever 3|, link 34 and rock arm 31 are so relatively arranged thatduring the final or delayed action of the inert member 29 an increasingleverage is provided to transmit the momentum of the inert member 29'tothe clamping member 26 through the rock arm 31, link 34, lever 3| andthe clamping member 2|. During the movement of the clamping member fromopen position (Figure 1) to closed position (Figure 5), the link 34moves into position where it/ approaches the radius of the arm 31.During the movement from the position shown in Figure 1 to that shown inFigure 5, the pivot 36 connecting the link 34 and the (rock arm 3! movesthrough a small are relative to the are of movement of the periphery ofthe member 29. However, as the link 34 approaches the radius of the arm31, the arc of movement of the pivot 35 becomes large relative to thearc of movement of the pivot 35 between, one arm of the lever 3| and thelink 34 and thereby provides an increasingleverage to transmit themomentum of the inert member 29 to the clamping member.

For the sake of compactness, or in order to locate the bracket 24, andthe work clamping mechanism within the vertical plane of the end edge ofthe overhanging end of the lower pressing element 2, the inert member 29extends inwardly or in the same general radial direction as the clampingmember 2|, when the clamping member is in closed or operative position.As seen in Figures 3 and i, the arm 22 is formed with a yoke 42, thearms of which are mounted on the pivot 23. The stud 38 is secured to alaterally extending lug 43 outside of the yoke 42 and the pivot 30 ofthe inert member 29 is a rock shaft on one end of which the inert member29 is mounted, and on the other end of which the rock arm 37 is mounted.The stop 4| is 10-.

Means is provided for latching the inert memher in its operatedposition. This means is shown in Figures 1 and 2 as a latch 45 pivotedbetween its ends at 46 to the bracket 24 and ,co-

acting at one end with the notch 4! in the inert 1 member 29, the latchbeing urged toward its latch- 1 mg position by a spring 49. When theinert member is moving upwardly from its position shown in Figurel tothat shown 'inFigure 2, the a peripheral surface 50 ofthe inert member29, this being a cam surface engages a roller 48 onthe latch 45 andpresses the latch to the left (Figure 2) against the actionof its spring49. Whenthe inert member 2'! swings under its momentum into the positionshown in dotted lines (Figure 1), i o the roller 48 enters thenotch 4'!and ho-lds the inert member in its operated position and fromrebounding. A suitable guide 5|,is provided for 1 enacting with the,latch 45 to prevent it fromdisplacement under the action of its.returning spring Hwhen the inert body ormember 29is in starting positionand before it engages the roller 48 i on the latch 45. This guide formspart of'the {release mechanism in the form shown in Figures 1, 2, 3 and4. The guide 5| is here shown as an angle lever pivoted at 52 to thebracket 25 and having an arm coacting with aroller 53 on the pin or studon which the roller' lt is also mounted,

the lever 51 also having an angle arm 55 coacting witha releaselever 56and located to limit the pivotal movement of the lever 5| insuoh 1position that the latch 45 can not pass out of l juxtaposition to theperiphery of i the inert body ormember 29. lhe release lever 56 islocated in itsstarting position by a stop 56?.

lnFilgure 3, the manually operated latch lever '56 is pivoted at 51 andshown as extending forward with its outer or handle end Within reach ofthe operator. However, the latch 45 may be clamp the tape'or bow '25onthe workon the l pressing element 2. During the movementof theinertmember into the position shown inb'roken lines (Figure 1), thelatch 45 moves into latch,-

in-g position to hold the inert member in itsoperated position. When thepress is opened the latch 45 is released, and the inert member drops bygravity toward startingposition and imparts an opening impulse to therock arm 31, link 34, lever 3|v and spring 32 to the clamping mem- WhatI claim is: i i 1. A work clamping mechanism for pressing machines whichincludes an element on which the work islaid, said mechanism including asupport, a manually shiftable work clamping member shiftably carriedbythe support, a normally bar 2!, thisbeirrg also facilitated by thespring 33.

inert'member shiftably carried by the support,

released automatically by the operation of the press, as the openingmovement of the press.

Referring to Figures 5 and 6, the means shown forreleasingthe latch l5is operated by the of the machine, a piston 59 workable thereinactuating mechanism of the press and comprises? acylinder 58 suitablycarriedbythe frame 3 andhaving its rod BI] pivoted at 5| to one of ;1

to the link ll]. The cylinderis connected through onthe frame 3 andhaving a diaphragm 54 there" inthrusting against a plunger 85 which inturn thrusts against the tail of the latch 45. The

cylinder is provided with a restricted inlet port 66 whichalsoconstitutes the outlet port. restricted to obstruct too rapid exhaustduring the power stroke of the piston 59. Whenthe press is being closed,the toggle links 8 and 9 straightenand retract the piston 59, drawingairinto the cylinder 58 through the port 66. When the press opens, thetoggle link I 0 moves upwardly and moves the piston to the right(Figures 2 and 6) and owing to the restricted outlet 66, forces airthrough thepipe 52 to the diaphragmchamber, actuating the diaphragm 54therein and through the plunger 65 moves the latch out of its latchingthe links of the toggle, here shown as pivoted a a pipe 62 to adiaphragm chamber 63suppo-rted motion transmitting {connections betweenthe clamping member and the inertmember to set the inert member inmotion upon the operating movement of the clamping member, said motiontransmitting connections including a 10st motion means permitting theinert member to initially lag behind the clampinamember and build up,momentum andvfinally overtake the clamping member and impart under itsmomentum an additional operating impulse to the clamping member.

2. A work clamping mechanism for pressing machines which includes anelement on which the work is laid; said mechanism including a support, amanually shiftable work clamping member shiftably carried by thesupport, a normally, inert member shiftably carried by the support,motion transmitting connections: between the clamping member and theinert member to set the inert member in motionupon the operatingmovement of the clamping member, said motion transmitting connectionsincluding a lost motion means permitting the inert member to initiallylag behind the clamping mmberand build up momentum and finally overtakethe clamping member and impact under its momentum an additionaloperating impulse to the clamping member, said lost motion connectioninclud ng yielding resilient means for transmitting the initial startingmovement to the inert member and for translating the additional im 1pulse from the inert member to the clamping member. j

3. A work clamping mechanism for pressing machines which includes anelement on which the Work is laid, said mechanism including asupiport, amanually operable work clamping member shiftably carried by thesupportand movable 3 into and out of coaction with said element, a nori mallyinert member shiftably carried by the support, motion transmittingconnections between position. When the pressis open and the latchreleased, the inert member Zllfalls by gravity, and

thus moves the clamping member 2! toward open its momentum. i

4. A work clamping mechanismvfor pressing the clamping member and theinert member to set the inert member in motion when the clamping memberis initially operated, said connections including means to permit theinertmember to initially lag behind the clamping member in its closingmovement, then gain lmomentum' and finally overtake the clamping memberand impart under its momentum an additional delayed operating impulse tothe clamping member when the clamping member approaches final clampingposition, the inert member beingmovable under its momentum intoatposition in which it tends to return by gravity to starting position,and 4 releasable means for holding the inert member o in the position towhich it has been moved by machines which includes an element on whichthe work is laid, said mechanism including a support, a manuallyoperable work clamping member shiftably carried by the supportandmovable into and out of coaction with said element, and an inertweight member pivoted to the support and normally hanging downward fromits pivot, motion transmitting connections between the clam-ping memberand the inert member to set the inert member in motion about its pivotin an upward arc, when the clamping member is initially operated, saidconnections including means to permit the inert member to initially lagbehind the clamping member in its closing movement and then gainmomentum and finally overtake the clamping member and impart under itsmomentum an additional delayed operatirrg impulse to the clamping memberwhen the clamping member approaches final clamping position,

the inert member being movable under its'momentum intoa position inwhich it tends to return by gravity to starting position. I

5. A work clamp mechanism for pressing machines comprising a suitablesupport, a manually operable clamping member including an arm pivoted tothe support, an inert member pivoted to the support, a lever pivotedbetween its ends to the support, a link connectingone arm of the leverand the inert member, eccentric to the axis of the inert member, andyielding means between the other armlof the lever and said arm, all soarranged that the clamping member when actuated sets the inert member inmotion and permits the same to gain momentum andexert additional delayedclamping efieot on the clamping member when the clamping memberapproaches final clamping position.

6. A work clamp mechanism for pressing machines comprising a suitablesupport, a manually operable clamping member including an arm pivoted tothe support, an inert member pivoted to the support, a lever pivotedbetween its ends to the support, a link pivoted to one arm of the leverand to the inert member eccentric to the axis of the inert member, andyielding means between the other arm of the lever and said arm, all soarranged that the clamping member when actuated sets the inert member inmotion and permits the same to gain momentum and exert additionaldelayed clamping effect on the clamping member when the clamping memberap- 2,864,196 r l a proaches final clamping position, the pivotalconnection between the link and the inert member being so located thatsaid pivotal connection has a small arc of movement relative to theperiphery of the inert member during the closing movement of theclamping member, and the link approaches the radius of said pivotalconnection as the clamping member closes, whereby the pivotal connectionbetween the inert member and the link then moves in a. comparativelygreat arc relative to the arc of movement of the pivotal connectionbetween the link and said one arm of the lever, thereby providing anincreasing leverage to transmit the momentum of the inert member to theclamping member.

7. A- work clamp mechanism for pressing machines comprising a suitablespport, a manually operable clamping member including an arm pivoted tothe support, an inert member pivoted to the support, a lever pivotedbetween its ends to the support, a link pivoted to one arm of the leverand to the inert member eccentric to the axis of the inert member, andyielding means between the other arm of the lever and said arm, all soarranged that the clamping member when actuated sets the inert member inmotion and permits the same to gain momentum and exert additionaldelayed clamping efiect on the clamping member when the clamping memberapproaches final clamping posit on, the pivotal connection between thelink and the inert member being so located that said pivotal connectionhas a small arc of movement relative to the periphery of the'inertmember during the closing movement of the clamping member, and

the link approaches theradius of said pivotal connection as the clampingmember closes, whereby the pivotal connection between the inert memberand the link then moves in a comparatively great are relative to the arcof movement of the pivotal connection between the link'an-d said one armof the lever, thereby providing an increasing leverage to transmit themomentum of the inert member to the clamping member, the inert memberbeing arranged to move under its momentum into a position by which itreturns by gravity in a retrograde direction, and releasable means forholding the inert member in its operated position. i

ERNEST DAVIS.

